As long poking around, decided to bring the court's decision. Last time it was a long decision, this time also walked on this rake. In the future I will probably walk again, as the problem is rare :). In General go, long harness for this.

During an upgrade. Dr.Web Enterprise Security from version 6 to 10 and version 10 to 11, be sure to follow the path. And fix the default settings.

Administration – server Configuration – Network – Transport – TCP/IP set the multicast group "" or "231.0.0.1", I have this location was specified the IP of the server and, accordingly, no single agent is unable porubitsya, as they have me on other subnets sit.

And I advise you to immediately record all IP addresses in the settings of access to groups and the server, these settings when you move from 10 to 11 version, all are lost. And as the reality has shown, these data are not transferred to the configuration export either, apparently that is why they are not transferred to the new configuration.